Comparison of models describing variation in the maximum dive duration.

The first section (above solid line) compares a fixed-effect only model with a mixed model, which includes random effects of species with a phylogenetic correlation structure. The second section (below solid line) compares different combinations of the fixed effect covariates within the model structure selected in the first section. Marginal and conditional coefficients of determination indicate the proportion of variance explained by the fixed effects only and the full mixed effects model, respectively [62].